It's often hard to like Paul Giamatti's characters, but even harder to hate them, which works both for and against Tom McCarthy's "Win Win."

It’s often hard to like Paul Giamatti’s characters, but even harder to hate them, which works both for and against Tom McCarthy’s “Win Win,” a disappointing domestic comedy in which all but the audience get what they want. Giamatti plays morally confused New Jersey lawyer Mike Flaherty, whose decision to take on an elderly client’s guardianship causes all sorts of trouble once the old man’s family shows up. Fox Searchlight no doubt hopes it has another “Little Miss Sunshine” on its hands, though “Win Win’s” intermittently amusing, R-rated blend of caricature and farce lacks that dysfunctional clan’s popular appeal.

In just two films (“The Station Agent” and “The Visitor”), McCarthy has proved himself a uniquely humanistic American humorist, capable of taking low-key dramatic scenarios and rendering them irresistible through careful attention to character and place. With “Win Win,” he opts for a broader, more generic approach, which leaves the ensemble feeling neither realistic nor particularly original.

Shooting mostly in closeup and underscoring the first act with bouncy, sitcom-style music, McCarthy gives his story a decidedly smallscreen feel as he establishes Mike’s cash-strapped existence. In such tight economic times as these, auds should have no trouble identifying with an over-stressed and under-compensated family man like Mike, though there’s something rather repulsive in the way the character is written: He can’t even be bothered to fix the noisy old boiler or the rotting tree that threaten to destroy his business and crush his house, respectively.

Mike wants an easy way out, and he finds it in Leo Poplar (Burt Young), an old man battling dementia whose sole wish is to live at home. As Leo’s court-appointed lawyer, Mike has little reason to go above and beyond with this case, until he discovers that Leo’s caregiver is entitled to a $1,500 monthly stipend. That’s all the incentive he needs to volunteer for the job.

Instead of letting Leo stay home, however, Mike dumps him in a retirement facility and proceeds to follow his passions, chief among which is coaching the wrestling team at his former high school, a responsibility he shares with unhappy friend Stephen Vigman (Jeffrey Tambor). As if all this discontent weren’t ulcer-inducing enough, McCarthy introduces yet a third amigo, Terry (Bobby Cannavale), still sore that his wife left him for the contractor he hired to fix their house. Granted, these are all realistic enough problems for the characters to be dealing with, but the same cannot be said for the coincidence that enters their lives in the form of Leo’s grandson, Kyle (newcomer Alex Shaffer).

One minute Mike is standing up in court claiming Leo’s surviving relatives can’t be reached, and the next, his long-lost kin (who just so happens to be a champion high school wrestler) rolls into town looking for a place to stay. The coincidences couldn’t be thicker if Ed McMahon walked in carrying an eight-foot check to solve all Mike’s financial problems, but Mike clearly isn’t one to ignore the door when opportunity knocks. He gives Kyle a basement room, enrolls him in school and turns the wrestling team’s losing record around.

Win-win, right? Not exactly, though it takes 75 minutes for anything resembling proper narrative conflict to enter the equation. Until then, “Win Win” spends its time alternating between home and school, where the characters engage in a level of low-key buffoonery befitting a half-hour network comedy — hardly the caliber of material we’ve come to expect from McCarthy.

Though selected for his wrestling skills, Shaffer is plenty plausible as an angry teen upset at his absentee mother (Melanie Lynskey). At practice, everyone worships Kyle for his bleached-blond hair, gnarly back tattoos and half-lidded stoner look — a throwback to Jeff Spicoli, minus the overt pot references — and whatever his problems, the kid genuinely seems better adjusted than any of the adult males around him. Nearly everyone else is cast according to type, the lone exception being Amy Ryan as Mike’s hilarious housewife, Jackie, a tough-love type who assures us her husband can’t be all bad, or else she would have left him long ago.

Spanning the better part of a semester, the film has pacing issues, with a number of scenes injected seemingly at random (as when, on more than one occasion, Mike sneaks a cigarette behind his wife’s back). The cloying opening score gives way to better musical choices as the story unfolds, with a terrific original song from the National over the end credits.